Apparatus for inside coating



May 23, 1944. MCGOWAN APPARATUS FOR INSIDE (BOATING Filed June 29, 1940INVENTOR AwWwL ATTORNEY Patented May 23, 1944 APPARATUS FOR INSIDECOATING Michael E. McGowan, Bloomfield, N. J., assignor to WestinghouseElectric & Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania Application June 29, 1940, Serial No. 343,229

(c1. si -1s) 7: Claims.

considered, is to automatically coat the insidesurfaces of vitreousenvelopes uniformly and in an economical and convenient manner.

Another object of my invention is the simultaneous application of aninside coating to a plurality of elongated vitreous envelopes or tubes.

A further object of my invention is the ro visionof apparatus forcoating the inside surfaces of elongated vitreous envelopes, comprisingupper and lower manifolds, or other coating devices, which grip theupper and lower end portions of said envelopes, and means for forcingcoating material to said envelopes, including means for preventing thecoating material from rising therein beyond a predetermined point, saidapparatus also including means for removing the excess coating materialtherefrom, and releasing the envelopes from said manifolds.

Other objects and advantages of the invention, relating to theparticular arrangement and construction of the various parts, willbecome apparent as the description proceeds.

In the drawing: g

Figure 1 is a plan of mechanism embodying my invention, with partsbroken away.

Figure 2 is an elevational view, partly in vertical section on the lineIIII of Figure 1, in the direction of the arrows. 7

Figure 3 is a vertical sectional view, on the line III-III of Figure 2,in the direction of the arrows.

Figure 4 is an enlarged sectional view of a portion of the top manifoldand associated envelope.

Referring to the drawing in detail, like parts being designated by likereference characters, there i shown a coating machine comprising aconveyor i l having a plurality of clips l2 and I3 between which areheld elongated vitreouse'n velopes or tubes M, such as those of thetypeemploy-ed in the manufactur of fluorescent lamps. That is, they maybe generally cylindrical hollow tubes, open top and bottom. The conveyorll rotates and is adapted to periodically index or stop after it haturned a distance equal to the circumferential distance between adjacenttubes it times the number of tubes handled at once.

Associated with the conveyor II is a table or bench 85 on which ismounted a standard or pedestal i6, carrying manifold guiding means orlugs I! and I8. Pivoted to said standard I6 is an upper movable device,such as a lever i9, carrying a manifold, reservoir, or other coatingdevice 2| with arm 20 adapted to reciprocate in thelug I1, and a lowermovable device, such as a lever 22, carrying a manifold, reservoir, orother coating device 23, with arm 38 adapted to reciprocate in the lugl8. In the present embodiment, the manifolds 2| and 23 are adapted togrip three envelopes or tubes M therebetween.

The upper manifold 2! has ports 2 25 and 26, through pipes 27, 28 and29, each of which extends slightly below an associated resilient orrubber seal 3|, as shown most clearly in Figure l. The purpose of thisconstruction is to prevent the coating material from extending quite tothe upper end of the envelopes or tubes is.

The lower manifold 23, ha a corresponding number of ports 32, 33 and Edin resilientor rubber nozzles 35, 3B and 31.

The, movable devices or levers i9 and 22 are operated through connectingrods 33 and 3d, the lower ends of which are pivoted to operating crankarms ll and 42, which may extend from a bell crank device 33, mounted ona shaft 36, pivoted in a bracket it! which is secured to the table 25. Alower arm M of the device 13 carries a roller engaged by an operatingcam 46, mounted on a cam shaft 47 pivoted in a bracket 50 which issecured to table It. The operating arm 4! is controlled by a spring 48,so that said manifolds 2| and 23 tend to move together and grip thetubes M disposed therebetween until they are withdrawn from said tubesby action of the cam 46 on the roller-carrying arm M.

The lower manifold 23 carries a flexible tube 29, also connected to apipe or tube 5i which extends into the bottom portion of a container orbottle 52 of coating fluid 53, the space between the tube 5| and theneck of the tube receiving aperture being closed by a cork or the like544.

In order to cause the coating materia1 53 to rise in the tubes or lampenvelopes it when desired, I provide a connection 55 to a compressed airline 56, through a shut-off valve 57?, and an automatic control valve58, which latter may be operated by cam 59 acting on roller 6i carriedby the arm 62 of hell crank lever 63, pivoted to a bracket 64, which maybe carried by the table i 5. Another arm 65 of the bell crank lever .63is actuated by a spring 66, so that its roller 6! is caused to remain inengagement with the operating cam 59, whereby the valve 58 is opened andclosed as desired.

In order to prevent the coating material from rising beyond the upperend portions of the tubes I4, I provide a special air relief valve 61,so adjusted that air is released therefrom when the coating fluid risesin the tubes l4 to the lower ends of, the tubes 21, 28 and 29.

As a safety precaution against inaccurate operation or failure of thevalve 61, the upper manifold 2| is formed with sufficient capacity tofunction as an overflow reservoir and accommodate a considerable amountof coating fluid, for example, all in the bottle 52, before itoverflows, so that said overfl'ow is returned to the reservoir 52; Saidupper manifold is also desirably provided with a filling funnel 68 inorder to allow for convenient replenishing of the supply of coatingmaterial.

The operation of the apparatus, previously described, is desirably asfollows:

The conveyor II is caused to rotate at intervals, successively bringing,in the present embodiment, groups of three tubes l4 into positionbetween the separated manifolds 2| and 23. When this indexing occurs,turning of the cam 46 with its shaft 41, as by drive shaft 69 throughbevel gears H, allows the spring 48 to operate the bell crank 43 andthereby push the manifolds 2| and 23 toward one another into fluid-tightengagement with the tubes or envelopes l4. As

the cam 46 allows this engagement, the cam 59 also causes the valve 58to open, admitting air' to the closed coating bottle 52, and forcingcoating fluid therein, which may be fluorescent material, up throughpipes 5|, 49, and the lower manifold 23 to a limit level on said tubes14, defined by the lower ends of the pipes 21, 28 and 29. The air reliefvalve 61 then operates to prevent the fluid from rising above, or muchabove, this level.

Continued turning of the cam shaft 41 first takes the pressure off thecoating fluid 53, as by closing the compressed air valve 58, andreleases the air in the bottle 52, whereby the coating fluid in the lampenvelopes or tubes 14 drains back into said bottle, the cam 46 thenoperating to cause a withdrawal of the manifolds 2| and 23 from thetubes l4 gripped therebetween under the action of the spring 48.

The conveyor I l of the machine then moves on to index the next threetubes for repeating the coating operation. The tubes which have beencoated may then be carried by the machine to baking or other means forfixing the coating thereto, after removing any excess from the bottomend portions thereof.

Although a preferred embodiment of my invention has been disclosed, itwill be understood that I do not wish to be limited to the employment ofmy machine for coacting vitreous envelopes of the particular characterdisclosed, as other embodiments of my invention will be apparent tothose skilled in the art and I, therefore, wish to be limited only bythe spirit and scope of the appended claims,

I claim:

1. Apparatus for coating the inside of vitreous envelopes comprising aconveyor carrying said envelopes, means for causing said conveyor toindex a plurality of said envelopes sequentially, a bracket mountedadjacent said conveyor and provided with lugs, levers pivoted on saidbracket, upper and lower manifolds operatively connected to said levers,arms extending from said manifolds to and slidable in said lugs to causesaid manifolds to reciprocate toward and away from one another uponmovement of said levers so as to either grippingly connect with orrelease indexed envelopes, a shaft carrying a plurality of cams, a bellcrank lever actuated by one of said cams and having one arm connected toone, and another connected to another of said manifold connected levers,means for turning said shaft so that said manifolds reciprocate towardand away from one another at predetermined intervals in synchronism withthe indexing of said conveyor, a container holding a supply of coatingfluid, means connecting said lower manifold to the fluid in saidcontainer, a source of compressed air, means connecting said source tosaid container over said fluid, another bell crank lever, a valve forcontrolling said compressed air, means connecting said other lever andvalve, said other cam operating said other bell crank lever to open saidcontrolling valve to admit air and force said coating fluid into saidlower manifold and connected envelopes, after the latter have beengripped between said manifolds, for flushing said fluid over the innersurfaces of said envelopes, and then close said valve and allow saidfluid to drain back into said container.

2. Apparatus for coating the inside of a vitreous tube comprising abracket provided with lugs, levers pivoted on said bracket, upper andlower reservoirs operatively connected to said levers, arms extendingfrom said reservoirs to and slidable in said lugs to cause saidreservoirs to reciprocate toward and away from one another upon movementof said levers, means for moving said levers to cause said reservoirs toreciprocate toward and away from one another at predetermined intervals,so that they either grippingly engage and connect with the ends of saidtube or release it, a supply of coating material,

- and means for forcing said coating material into said'lower reservoirand over the inner surface of said tube, and then allowing it to drainback into said supply.

3. Apparatus for coating the inside of a vitreous tube comprising abracket provided with lugs, levers pivoted on said bracket, upper andlower reservoirs operatively connected to said levers, arms extendingfrom said reservoirs to and slidable in apertures in said lugs to causesaid reservoirs to reciprocate toward and away from one another uponcorresponding movement of said levers, means for operating said leversto effect desired reservoir movement at predetermined intervals, wherebythe latter are adapted to either grippingly engage and connect with theends of said tube or release it, a bell crank lever having one armconnected to one and.

another connected to another of said reservoirconnected levers, meansfor operating said bell crank lever so that said reservoirs reciprocatetoward and away from one another at predetermined intervals, a containerfor a supply of coating fluid, and means for forcing contained fluid:into said lower reservoir and over the inner surface of said tube, andthen allowing it to drain backinto said reservoir.

4. Apparatus for coating the inside of a vitreous tube comprising abracket provided with lugs, levers pivoted on said bracket, upper andlower reservoirs operatively connected to said levers, arms extendingfrom said reservoirs to and slidable in said lugs to cause saidreservoirs to reciprocate toward and away from one another uponcorresponding movement of said levers, a shaft carrying a cam, meansactuated by said cam and. having. one part connected to one and.

another part connected to another of said reservoir-connected levers,means for turning said shaft so that said reservoirs reciprocate towardand away from one another at predetermined intervals, a container for a,supply of coating material, and means for forcing contained materialinto said lower reservoir and over the inner surface of said tube, andthen allowing it to drain back into said reservoir.

5. Apparatus for coating the inside of a vitreous tube comprising abracket provided with lugs, levers pivoted on said bracket, upper andlower reservoirs operatively connected to said levers, arms extendingfrom said reservoirs to and slidable in apertures in said lugs to causesaid reservoirs to reciprocate toward and away from one another uponcorresponding movement of said levers, means for operating said leversto eflect desired tube gripping or releasing movement of said reservoirsat predetermined intervals, a container for a supply of coatingmaterial, means connecting said lower reservoir to said container, asource of compressed air, means connecting said source to said containerover said material, a bell crank lever, a valve for controlling saidcompressed air, means connecting said bell crank lever and valve, andmeans for operating said bell crank lever to open said valve to admitair and force said coating material into said lower reservoir andconnected tube, after the latter has been gripped between saidreservoirs, for flushing said material over the inner surface of saidenvelope, and then close said valve and allow said material to drainback into said container.

6. Apparatus for coating the inside of vitreous envelopes comprising aconveyor therefor, means for causing said conveyor to sequentially indexa plurality of said envelopes, a standard mounted adjacent said conveyorand provided with guiding means, upper and lower coating-fluidcontainers slidably mounted with respect to said'guiding means,operating means movably carried by said standard and connected to saidcontainers, means for driving said operating means to cause saidcontainers to reciprocate toward and away from one another, so as toeither grippingly connect with or release indexed envelopes, cam means,bell crank lever means actuated by said cam means and having armsconnected respectively to said container operating means, means forturning said cam means so that said containers reciprocate toward andaway from one another at predetermined intervals in synchronization withthe indexing of said conveyor, a reservoir holding a, supply of coatingfluid, means connecting said lower container to the fluid in saidreservoir, a source of compressed air, means connecting said source tosaid reservoir over said fluid, another bell crank lever, a valve forcontrolling said compressed air, means connecting said other lever andvalve, and said other cam being so shaped that it will operate saidother lever and connected valve to cause air to force said coating fluidinto said lower container, flush said fluid over the inner surfaces ofsaid envelopes while the latter are gripped between said containers, andthen remove the air pressure and allow said fluid to drain back intosaid reservoir.

7. Apparatus for coating the inside of a vitreous tube comprising astandard provided with guiding means, upper and lower coating-fluidcontainers slidably mounted with respect to said guiding means,operating means movably carried by said standard and connected to saidcontainers, means for driving said operating means to cause saidcontainers to reciprocate toward and away from one another atpredetermined intervals, so that they either grippingly connect with theends of said tube or release it, a supply of coating material, and meansfor forcing said coating material into said lower container and over theinner surface of said tube, while gripped between said containers, andthen allowing it to drain back into said supply.

MICHAEL E. McGOWAN.

